Eventually, every Linux user opens an app and finds a generic placeholder icon staring back from their dock/panel. It looks like the dock is broken, but it almost never is - the cause is a single line in the app’s .desktop file, and it only takes a minute to fix. Here’s how to find it and fix it yourself, on any desktop.

As the maintainer of Plank Reloaded, the most common bug report I get is “this app has the wrong icon.” It’s almost never the dock - it’s a broken StartupWMClass in the app’s .desktop file. So I wrote up how to find the right value on X11, Wayland, and KDE, and why deleting the line often fixes it.

  • angel@sopuli.xyz
    1·
    2 days ago

    Hmm, but I thought the StartupWMClasses in the desktop files are correct? I thought the issue is that firefox-nightly uses the firefox class in addition to the firefox-nightly class

      • angel@sopuli.xyz
        1·
        2 days ago

        I see, so I could remove it, but wouldn’t I still see the same behavior, since firefox nightly apparently also uses the firefox window class?